323. Praseodymium Doping in Ceria-supported Palladium Nanocatalysts as an Effective Strategy to Minimize the Inhibiting Effects of Water During Methane Oxidation

Sabrina Ballauri, Enrico Sartoretti, Min Hu, Carmine D’Agostino, Zijuan Ge, Liang Wu, Chiara Novara, Fabrizio Giorgis, Marco Piumetti, Debora Fino, Nunzio Russo and Samir Bensaid; Applied Catalysis B; (2022); DOI: 10.1016/j.apcatb.2022.121898

The present study reports an improved design for Pd/Ce-Pr catalysts. Pd-impregnated nanostructured ceria-praseodymia catalysts with different compositions were comprehensively characterized and tested for dry and wet methane oxidation. The strong PdO-PrOx interactions, detected via XRD, TPR/TPO, Raman and HRTEM analyses, retain Pd mainly in its oxidized form in the materials with high praseodymium content, thus resulting in a lower activity. Conversely, the introduction of a limited amount of Pr in ceria allows to obtain a more active catalyst (2% of Pd supported on a mixed oxide with 10% of Pr) than the typical Pd/CeO2 systems. Hence, the simultaneous presence of Pd in its reduced and oxidized forms results to be a key factor for high activity. Additionally, the higher hydrophobicity of this sample, investigated through NMR and in situ FTIR, markedly reduces the H2O inhibition effect typical of Pd-based materials, paving the way for using this system in real applications.